For the pastry, rub the butter into the plain flour. Stir in the icing sugar, egg yolk and water, then mix it together with your hands until you are left with a smooth elastic dough. Wrap in cling film and pop in the fridge for 45 mins to firm up.

Preheat the oven to 180C/350F/Gas 4 and grease a 20cm loose bottomed sandwich tin. Break a third of the dough off to save for the lid, then for the other two thirds roll out on a smooth surface, big enough to fill your tin. Transfer the dough to the tin and press to the sides. If it breaks a bit it's no problem as you can use any excess dough to repair. Line with baking paper, fill with baking beans and bake in the centre of the oven for 15 minutes. Remove from the oven, take out the beans and paper, then return to the oven for 2 minutes to dry out. Remove again and set aside to cool a little. Turn the oven down to 170C/325F/Gas 3.

Tip the apples into a large pan with the vanilla, cinnamon and syrup. Leave to cook gently on a low heat with the lid on for about 15-20 minutes, stirring occasionally. I found some of the apples broke down more than others, but I didn't mind that. Remove from the heat and set aside whilst you finish off the pie.

Spoon the cooked apples into the part baked pie case. Fit as many in as you can. Roll the last of the pastry out into a lid shape. Brush the edges of the cooked pie case with a little beaten egg, then lay the lid on top and press the edges to secure. Make a little star in the top with 5 points of a knife, brush over with more beaten egg and place in the oven for 30 minutes, until brown on top. Remove and leave for 10-15 minutes to cool a little. Carefully remove from the tin and dust with caster sugar. Serve hot with cold ice cream, cold with hot custard or any way you fancy!